1. Field of the Invention
This invention relates to a computing machine (or calculator) with an inequality computation and display function.
2. Description of the Related Art
One of the conventional electronic computing machines which have an inequality computation and display function is a graphical function calculator which has a graphical display function according to a desired function expression.
For example, with the graph function calculator described in Jpn. Pat. Appln. KOKAI Publication No. 08-180197, when the inequality Y>f(X) is input, a locus of a graph corresponding to Y=f(X) is drawn and displayed and further the range of solutions corresponding to the inequality is displayed in the form of a hatched area or a painted area to distinguish the range from the remaining area.
Furthermore, as described in Jpn. Pat. Appln. KOKAI Publication No. 2000-242801, an inequality processing device has been considered which displays on a number line graph the range of solutions corresponding to the input inequality.
The conventional graph function calculator has a large-screen display unit and can display a graph and represent the solutions of an inequality in graph form in an easy-to-understand manner. However, for example, a standard scientific electronic calculator with a display unit capable of displaying only about three lines of character strings cannot display a graph as described above and therefore has the problem of being incapable of representing an image of the solutions of an inequality in an easy-to-understand manner.